1. Know the language.
Studying biology is like studying a foreign language. You need to learn the vocabulary if you hope to be successful. As you read, make a note of any words that are unfamiliar to you and look up the definitions. No glossary? Try a Google search in the form of "define: search term".

2. Read the Book.
Take the cellophane off the cover and start reading. Yes, really! Remember that most Biology texts don't read like a good novel (or even a bad novel, for that matter) - take your time and backtrack as necessary. Also, take advantage of any online resources or CDs that may be associated with your text.

3. Pay attention to the pictures.
Students often ignore the figures, tables, charts, graphs, etc. in their textbooks because they feel that stopping to analyze them will only add to the time it takes to read the assigned text. You may actually find that it is easier to study the figures first (a picture is worth 1000 words...) and then to go back and fill in the details by reading the pertinent text.

4. Ask questions. Find answers.
As you read and study the figures, try to keep the "big picture" in focus and ask yourself some questions. Why does (whatever) work this way? How did (someone) figure out this mechanism? What would happen if (whatever) stopped working? Now, as you continue to read, focus on finding answers to these questions.

5. Be curious.
It is difficult (if not impossible) to learn if you remain disengaged from the subject. Whether you a Biology major or non-major, take advantage of your time in the course. Look for the applications of the material that you are studying. Check the news, do a quick search on Google Scholar, add a science feed to your RSS reader. Becoming an active participant in your education will pay dividends.

By Definition:
Genes are specific sequences of DNA found on our chromosomes. Each gene carries the information for the production of a specific polypeptide. One or more polypeptides make up our proteins. Based on the results of the Human Genome Project, it is estimated that humans have 20,000-25,000 genes.

So what?
Proteins are the molecules that carry out the work of the cell and you are composed of trillions of cells. So, as the cells go, you go. If specific proteins are not made at the right time or are defective in their function, certain cells may be unable to carry out specific tasks and you may display the characteristics of a genetic disorder or other disease.

An Example:
Sickle cell anemia is common genetic disorder among the African American population. This particular disease is the result of a single mistake, called a mutation, in the gene for a protein called hemoglobin. Hemoglobin proteins are found in red blood cells and are responsible for carrying oxygen throughout the body. Red blood cells are typically shaped like smooth doughnuts and they move easily through the blood vessels. Red blood cells having the defective hemoglobin take on a "sickle" shape (think of the letter "C" with pointed ends) and these sickled cells form clumps that get stuck in the blood vessels.

Consider This:
The human genome is made up of more than 3 billion pairs of chemical letters (called nucleotides). A single mistake, in the case of sickle cell anemia, results in a heritable genetic trait.

Resources
What is Sickle Cell Anemia?
What is a Gene?